Incandescent electric lamp



A' iil3, 1934. A. EQALLENA 1,953,456

INCANDESGENT ELECTRIC LAMP Filed May 27. 1952 2 Sheets-Sheet 2 I M L manner ATI'CRNE I INVENTOR I Q UNIT D STATES Patented Apr. 3,- 1934 Howard E. Allen, Nutley,

Pennsylvania INCANDESGEN'I ELECTRIC LAMP N. J., assig'nor to Westinghouse Lamp Company, a-corporation of Application May 21, 1922, Serial No. 613,896

2 Claims. (01. 176-39) This invention relates to incandescent electric lamps and relates more particularly to lamps employed for projection purposes.

In the manufacture of projection lamps it is necessary that the light source or filament be lie in staggered spaced relation. In the operation of such character that it will generate the requisite amount of light in a manner as to insure a uniform distribution over the entire field of illumination. V

It has been found in practice that a desirable source of illumination for projection work is one in which a solid body or point of light is obtained, because of the fact that all lens systems have a definite focal point and it is essential for clearimages that the-light proceed as nearly as possible fromtthe focal point.

Although the ideal condition is not possible to obtain, it is closely approximated in the design of projection lamps and particularlyin the filament arrangement of the lamp shown in Patent 1,313,857 of A. R. Dennington issued August 15), 1919. In the construction shown in this patent the filament has a plurality of closely wound coils which coils are mounted in such manner adjacent the focal point that each is enabled to project a maximum portion of its illumination in the desired direction.

In accomplishing this, the light source comprises a plurality of straight sections of helically coiled filament wire of substantially equal size,- approximately half of the coils being disposed in parallel relation to each other in a plane substantially normal to the projecting axis of the lamp. The spaces intermediate the coils being v substantially equal in width to the diameter of the coils and the remaining coils are disposed behind the first named coils and in a line with the intermediate spaces.

By this arrangement, a substantially uniform illuminating source comprised of all the flla'" mentary sections is presented in the direction of the projecting axis.

In accomplishing the above, the filamentary wire, such for example as drawn tungsten, is wound to give a plurality of what are termed spaced coils which means that a coil section is formed and then a straight section of wire which connects another coil section and so on. This length of spaced coils is then formed by bending at the straight portions to give a zigzag arrangement of coiled filamentary bodies which arethen arrangedso that substantially half or one group of the coiled sections are in one plane and the other half or group in another plane. The coils in each plane are then positioned so that they of a projection lamp,-it is necessary to employ a hight temperature filament and during the operation of the lamp it has been found that the high temperature conditions make it difllcult to properly support the filamentary sections so asto maintain them in the desired space relation, ow-

ing to distortion under the elevated temperature which tends to causethe filamentary sections to move relative to each other, particularly under the action of alternate heating and cooling.

It is an object of the present invention therefore to provide an improved supporting structure, a plurality of coiled sections so that they will retain their desired and-effective spaced relation under variations in temperature conditions.

Another object of the present invention is to provide a structure wherein the coiled sections may be readily and conveniently mounted in the desired staggered spaced relation and at the same time will be resiliently supported to dissipate vibration.

Another object of the present invention is to provide a filament mount of a simple and rugged construction so arranged as to simplify the mounting of the filament.

Other objects and advantages of the present invention will be apparent in the following description together with the accompanying drawings in which:

Fig. 1 is an enlarged view of a projection lamp showing the filament and mount in accordance with the present invention and in which the bulb is shown in cross section;

Fig. 2 is a view taken on line 11-11 in Fig. 1;

' Fig; 3 is a view taken on line IIIlII in Fig. 1 looking upwardly in the direction of the arrows;

Fig. 4 is a view taken on line IV-IV in Fig. 1;

Fig. 5 is a diagrammatic view of the filament showing the component parts thereof and the cpnnected supports;

Fig. 6 is a view of a lamp showing a modification of the present invention;

Fig. 7 is a view taken on linejVIL-VII in Fig. 6; and

Fig... 8 is a diagrammatic view of the filaments disposed in multiple relation-,-together with connected supports.

A lamp constructed in accordance with the present invention'shown in Fig.'l'may comprise a bulb 10 provided with a flare tube 11 having a press 12. The flare tube may be sealed in the usual manner at 13 to the bulb 10 which latter may contain an inert atmosphere such as nitrogen or argon and the usual exhaust tube 14 for sealing thebulb from the atmosphere Within the bulb and extending from the press 12 are conductive support members 15 and.16 having their lower ends imbedded inithe press and connected with lead wires 1'? and 18 respectively. Intermediate .the members -15 and: 16 and having their lower endsimbeddedinthe press 12 are support members or spuds 19 and 20. These spuds may be comparatively rigid and serve to support the filamentary body 21 which is suspended on relatively flex- In the selected embodiment of the insertion shown the filamentary body 21 consists of two groups or series of coiled sections of filament. Each group comprises a plurality of spaced coiled sections positioned to lie in a common plane. The two groups are positioned in closed-spaced relation and with the coiled sections parallel.

For the purpose of obtaining a solid body of light,

the coils are so positioned that a coiled section is disposed opposite to the spaces between the opposite coiled sections. Thus, each group or series of coils may be initially held in the desired space relation and may be mounted in position as shown by looping, the relatively straight portions of wire 21 between the coiled sections, over hooked portions 28 provided at the ends of the carrier members 22, 23, 24 and 25.

In the present construction, each group contains four sections of coiled filament so that the carrier members 22 and 23 may support the group of coils designated as A and carrier members 24 and 25 may support the group of coils designated as B. The relatively straight portions of filament connecting the coiled sections at the lower side of group A, may beheld in position by connecting one end of, the anchor member 29, the opposite end of which may be imbedded in the glass bead 26.

For the purpose of passing electrical energy through the two groups of coiled sections, terminal 31 of group A is connected with the upper end of the support member 15 and terminal 32 of group A is connected to the upper end of spud 20. Terminal 33 of group B is connected to the support member 16 while'terminal 34 of the group of coiled sections B is connected with the spud 19. In operation, therefore, electrical energy flowing through lead wire 1'7 fiows through member 15, group of coiled sections A, through spud-20, wire or bridge member 27, spud 19, group of coiled sections B, support member 16 and through lead wire 18. v

By reason of the present construction, the groups of coiled sections may be conveniently mounted in their desired spaced relation. Whereas, heretofore, when shaping the filamentary body in a series of nnected coiled sections it was diflicult when bending the relatively straight portions between the filament to maintain the desired spaced relation since, when so bending the said straightportions, it was necessary to bend them at an angle to the plane in which the filament sections were disposed.

Furthermore, in structures as heretofore used, the bending of the straight portions at an angle to the normal plane thefilamentary sections had a tendency, when the lamp was operated, to exert a pull to bring the filaments in closer relation or otherwise distort or disturb the uniformity necessary for good results. In addition, it will be evident that whereas inthe manufacture of a lamp of the present character, the groups of filamentary sections, disclosed in' the present invention, may be conveniently shaped prior to mounting. This is possible because it is only necessary to bend the straight portions between each section in an are leading from one filamentary section to another and each group may, therefore, be accurately shaped and, when once set, the

spuds 19 and 20 are electrically connected with coiled sections-will retain their uniform relation. Whereas, when making the coiled sections in one continuous piece, dimculty was encountered in the initial shaping operation due to the bending of the straight portions of filament in two different planes.

Although the foregoing description is concerned with alight source comprised of groups of coiled sections arranged in series, it is to be understood that the arrangement of the groups may be in parallel or multiple as shown in Figs. 6 and 8. With this arrangement, the structural features will be generally the same except that a non-conductive body or bead 40 is provided with supporting connector pieces 41 and 42 secured to the spuds 19 and 20 and to supports 15 and 16 respectively. In the construction where the filaments are in series, the cross piece 2'? extends through the bead and connects to the spuds 19 and 20 to connect, the filaments.

The present construction insulates one spud from the other. In this case, the circuit, as shown more clearly in Fig. 8, includes the leading-in or conductive supports 15 and 16 and since the the supports 15 and 16 respectively, the terminals of groups 43 and 44 of filaments may be disposed in multiple by connecting their terminals at one side to spud 19 and support 15 and their terminals at the other side to support 16 and spud 20 respectively.

It will be noted that with the present multiple arrangement of groups of filamentary sections, the supporting structure may remain substantially the same insofar as it serves to effectively support the two groups of filaments in the desired resilient and spaced parallel relation.

Inasmuch as the effectiveness of a lamp of the present character depends on the symmetrical and definite relation of the filamentary sections, it is essential to maintain such uniformity throughout the life of the lamp. With the present construction, the most ideal conditions are approached in maintaining the filamentary sections so that a uniform solid body of light for projection purposes will be obtained.

Although a preferred embodiment of the invention is shown anddescribed herein, it is to be understood that modifications may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim:

1. An incandescent electric lamp comprising a bulb, a press within said bulb, a pair of conductor support members extending from said press. a pair of intermediate support members extending from said press, a cross member connecting said last mentioned support members, an insulative bead on said cross member, a filament and means carried by said bead for resiliently supporting said filament.

2. An incandescent electric lamp comprising a bulb, a press extending into said bulb, a pair of conductive support members extending from said press, a second pair of support members extending from said press, a conductive cross piece connecting said second support members, a nonconductive bead on said cross piece, a group of sections of coiled filament, resilient members extending from said head for engaging the upper portions of said sections and means connected with said bead for engaging lower portions of said sections. 

